Spring biased fixing-clips for maintaining specimen carriers for electron microscopy in position



Feb. 1967 F. GRASENICK ETAL 3,307,035

SPRING BIASED' FIXING-CLIPS FOR MAINTAINING SPECIMEN CARRIERS FOR ELECTRON MICROSCOPY IN POSITION Filed June 29, 1964 I 3/67 DPS Gr zs77ick FI-LZ Z Siegfried Ge 5 United States Patent SPRING BIASED FDflNG-CLIPS FOR MAINTAIN- ING SPECIIVIEN CARRIERS FOR ELECTRON MI- CROSCQPY IN POSITION Fritz Grasenick and Siegfried Gessner, both of 12 Rechbauerstrasse, Graz, Austria Filed June 29, 1964, Ser. No. 378,870 Claims priority, application Austria, July 3, 1963, A 5,319/63 V 3 Claims. (Cl. 25049.5)

The invention relates to a device for maintaining specimen carriers in position on a specimen plate, particularly for specimens used in electron microscopes, and to be fixed in a treatment chamber. The basic purpose of the invention consists in providing a device by means of which the specimen carriers can be speedily attached to and removed from any clamp member of the specimen plate. In certain cases, such as when the specimens are to receive preliminary treatment for electron microscopes, it is necessary to provide positive thermal contact between the specimen carrier and the cooled and/ or heated specimen plate so as to bring the objects to be treated quickly to the desired temperature.

According to the invention this is achieved by locating the specimen plate in one or several places of a clamp member fixed thereon by means of fixing clips extending through said mount and prestressed towards the clamping area of said clamp member. The said fixing clips can be lifted by means of appropriate elements after overcoming the prestress. With a holder of this type it is possible to fix a number of specimen carriers of various dimensions, if necessary, in a simple manner and within a short time on the clamping surface of the plate in such a way as to keep them securely clamped down even on an inclined plate. The fixing clips may be so designed as to provide permanent access to the clamped specimen carriers from all sides for the purpose of giving them the necessary preliminary treatment. The fact that the specimen carriers are permanently pressed against the plate by means of the fixing clips also ensures a positive heatconducting connection between these elements.

According to the invention the fixing clips preferably comprise a U-shaped clip with inwardly bent prongs for grasping the specimen carriers, the crossbar of the clip having extensions in the shape of fiat springs hearing from below on the clamp member. The fixing clip which is integral with its spring element does not require additional means of attachment to the clamp member and constitutes a plain and inexpensive element. With the specimen carrier clamped down, the two prongs of the fixing clip only protrude above the clamping surface of the plate, so as not to obstruct the treatment operations, such as the application of coatings by vaporization.

According to a further feature of the invention, a two armed lever is provided as an actuating means between the clamp member and the specimen plate, one extremity of the said lever acting on the crossbar of the fixing clip, the other extremity being accessible from the side of the clamping surface of the specimen plate for the purpose of inserting a pin or the like. This design greatly facilitates the operation of the holder. The specimen carrier can be fixed or removed from the side of the clamping surface, if necessary also from the inside of the treatment chamber through appropriate openings in the wall of said chamber. This is particularly advantageous for cooling chambers, as the exchange of specimen carriers is possible without a major interruption of the treatment, the temperature of the specimens in the chamber remaining practically unchanged.

Further details of the invention will appear from the following description of several embodiments of the inice vention with reference to the accompanying drawings in which:

FIG. 1a is a plan view of a specimen plate according to the invention,

FIG. lb is a partial plan view of the clamping plate,

FIG. 2 is a cross-sectional view of the specimen plate according to the invention taken on line II II of FIG. 1a in the direction of the arrows, and

FIG. 3 is an axial cross-sectional view of the specimen plate taken on line III-IH of FIG. 1a in the direction of the arrows.

FIG. 4 is an axial cross-sectional view of another embodiment of the invention, and

FIG. 5 is a cross-sectional view of the specimen plate of the first-mentioned embodiment of the invention taken on line V-V of FIG. 2.

FIGS. 2 through 5 are illustrations on an enlarged scale as compared with FIGS. 1a and 1b.

A circular clamping plate 2 is concentrically secured by means of screws 12 to the upper side of a fiat circular specimen plate 1. The plate 2 comprises a number of raised circular areas on the side of the clamping surface 2', said areas serving to receive the specimen carriers 5 to be secured to the specimen plate 1. In these places of the clamp member 2 fixing clips 3 are inserted which are U-shaped clips with inwardly bent prongs 4 encompassing to grasp the specimen carriers 5 and located on the side of the clamping surface 2 toward which they are held under tension. For this purpose, the crossbar 6 of the fixing clip 3 located below the clamp member 2 is provided with fiat spring-like extensions 7 on both sides, the said extensions hearing from below on the clamp member 2 of the specimen plate 1.

Between the clamp member 2 and the specimen plate 1 a two-armed lever 8 associated with one fixing clip each is supported by means of a supporting web 14 and tiltable about a horizontal axis. One extremity 9 of this twoarmed lever 8 bears on the fixing clip 3 directly below the crossbar 6. The other extremity 10 of the lever 8 extends beyond the outer periphery of the clamp member 2 (FIG. 2) or, where the fixing clip is arranged concentrically (FIG. 3), is accessible from the side of the clamping surface 2' by a bore 13. To ensure positive engagement of a rod for the operation of the holder, a notch 11 is provided in the extremity 10 of the two-armed lever 8.

In the embodiment of the invention illustrated in FIG. 4, a bore 13' is provided for the operation of the holder instead of a lever, a rod or similar operating member being moved close to the crossbar of the fixing clip 3 through said bore if and as required.

Other variants of the holder can be devised without exceeding the scope of the present invention. For example, other tensioning means, such as helical springs or the like could be provided for the fixing clips instead of flat springs. Furthermore, the same specimen plate could be equipped with fixing clips of various sizes and shapes in order to clamp down different types of specimen carriers, all of which may be subject to the same treatment.

We claim:

1. A device for maintaining specimen carriers in position on a specimen plate in a treatment chamber, particularly for preparations used in electron microscopy, comprising a specimen plate, a clamp member detachably mounted on the said specimen plate and provided with a plurality of apertures, fixing clips partially located between the specimen plate and the clamp member and extending through the said apertures, a spring for each fixing clip located between the said specimen plate and the clamp member and bearing upon the said fixing clip in the direction of the specimen plate, and lever means for lifting the said fixing clips against the bias of the said springs, the said lever means being tiltably arranged between the said specimen plate and the said clamp member in such a manner as to be operated from outside.

2. A device as claimed in claim 1, wherein the said fixing clips are U-shaped, comprising a crossbar and two prongs inwardly bent for the purpose of encompassing the said specimen carriers, the spring biasing the said fixing clip being designed as a fiat spring and integral with the fixing clip.

3. A device as claimed in claim 1, wherein the said fixing clips are U-shaped, comprising a crossbar and two prongs inwardly bent for the purpose of encompassing the said specimen carriers, the spring biasing the said fixing clip being designed as a fiat spring and integral with the fixing clip, and in which the said lever means comprises a lever located between the said specimen plate and the clamp member and supported between its extremities by the specimen plate, one extremity of the said lever means bearing upon the crossbar of the said U-shaped fixing clip and the other extremity of the said lever means being accessible from the outside.

References Cited by the Examiner UNITED STATES PATENTS RALPH G. NILSON, Primary Examiner.

W. F. LINDQUIST, Assistant Examiner. 

1. A DEVICE FOR MAINTAINING SPECIMEN CARRIERS IN POSITION ON A SPECIMEN PLATE IN A TREATMENT CHAMBER, PARTICULARLY FOR PREPARATIONS USED IN ELECTRON MICROSCOPY, COMPRISING A SPECIMEN PLATE, A CLAMP MEMBER DETACHABLY MOUNTED ON THE SAID SPECIMEN PLATE AND PROVIDED WITH A PLURALITY OF APERTURES, FIXING CLIPS PARTIALLY LOCATED BETWEEN THE SPECIMEN PLATE AND THE CLAMP MEMBER AND EXTENDING THROUGH THE SAID APERTURES, A SPRING FOR EACH FIXING CLIP LOCATED BETWEEN THE SAID SPECIMENT PLATE AND THE CLAMP MEMBER AND BEARING UPON THE SAID FIXING CLIP IN THE DIRECTION OF THE SPECIMEN PLATE, AND LEVER MEANS FOR LIFTING THE SAID FIXING CLIPS AGAINST THE BIAS OF THE SAID SPRINGS, THE SAID LEVER MEANS BEING TILTABLY ARRANGED BETWEEN THE SAID SPECIMEN PLATE AND THE SAID CLAMP MEMBER IN SUCH A MANNER AS TO BE OPERATED FROM OUTSIDE. 